Todd Carrico wrote:

Anderson Ed wrote:

I am inclinded to agree with your recommendation, Tracy.  Having
researched the topic a little more, a new engine comes with the nitrate
coating on the end/side housings which a rebuilt will not have if it has
been lapped/ground.  One source indicates that expected life of a
housing without the nitrate coating is around 50,000 miles compared to
200,000 with - a significant difference if true.  I am finding that the
asking price for a used 89-92 turbo ranges from $1000 - up depending on
condition. Then add in the cost of housings and different rotors and
pretty soon you can easily be over $3K.  Besides if I ever decided I
wanted to add a turbo I already have the engine - I wonder what that
would do for trying to keep the oil temp down {:>}.

Thanks

Ed Anderson

Ed,
At Superior, one of the reasons we went with through hardened barrels was
because Nitrided barrels are more suceptable to corrosion.  Nitriding can
get pretty High Rc ratings (low case depth though), and through hardeneing
gave us the hardness that we needed.  Also, Nitriding is a process that can
be done after lapping, I think.  I have never priced it, but it may cheaper
to have them lapped and nitrided.  Cheaper than $3k I would imagine.

tc

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